The present invention relates to a solar cell module to be connected to a cable for connecting the solar cell modules to each other, a method of connecting the solar cell module, a method of installing a plurality of solar cell modules on an installing body such as the roof of a house without using a rack, a solar cell module to be connected to a ground wire for making a ground connection, and a method of grounding the solar cell module.
Photovoltaic power generation for converting light energy into electrical energy by using a photoelectric conversion effect has been widely used as means for obtaining clean energy. Besides, with an improvement of the photoelectric conversion efficiency of solar cells, the number of private houses using a photovoltaic power generation system has been increasing.
In such a photovoltaic power generation system, a plurality of solar cell modules, each comprising a solar cell portion where a plurality of stages of solar cells are connected in series, are connected to a trunk cable, and a DC output of the solar cell modules collected through the trunk cable is converted into an AC output by an inverter and the AC output is outputted.
There is a known method of connecting solar cell modules, which facilitates wiring in connecting a plurality of solar cell modules to a trunk cable (for example, Japanese Patent Application Laid-Open No. 11-299126/1999). According to this conventional connecting method, the solar cell module can be easily connected to the trunk cable by connecting a male connector or a female connector provided on the trunk cable to a female or male connector provided on the solar cell module.
In the above-mentioned conventional method of connecting solar cell modules, there is a problem that the male and female connectors become expensive in order to improve their waterproof performance, and there is also a room for improvement of the waterproof performance at the connected section.
Moreover, in a photovoltaic power generation system for private houses, a technique of installing a plurality of solar cell modules directly on a building material of a roof (sheathing roof board) without using a rack has been employed in addition to a technique of installing a plurality of solar cell modules on a metal rack.
In order to make the appearance of the solar cell modules similar to the roof, the method of installing a plurality of solar cell modules on the sheathing roof board often employs a so-called stepped-roofing structure in which a plurality of solar cell modules are installed stepwise from the ridge side toward the eave side in such a manner that the ends of adjacent solar cell modules overlap each other. In this case, since the waterproof property is obtained by engagement of adjacent solar cell modules, it is difficult to replace the solar cell modules on a piece by piece basis, and thus there is a problem that this method can not respond efficiently to a breakdown or installation defect of the solar cell modules. Furthermore, there are problems that the installation involves complicated work processes and it takes a long time to perform the processes.
In the case where a plurality of solar cell modules are installed on a metal rack, since a metal frame portion on the periphery of the solar cell module is fixed to the rack, the periphery of each solar cell module and the rack have an equal electric potential, and therefore each solar cell module can be grounded if the rack itself is connected to a ground wire. On the other hand, when a plurality of solar cell modules are installed directly on the building material of the roof (sheathing room board), since the rack is not provided, it is necessary to additionally provide a wire for connecting each solar cell module to the ground wire on the periphery of each solar cell module so as to ground the solar cell modules, and there is a demand for simplicity of connection with the ground wire.
An object of the present invention is to provide a solar cell module capable of being easily connected to a cable for connecting solar cell modules to each other, at a low cost, and of ensuring a high waterproof property at the connected section, and to provide a connecting method thereof.
Another object of the present invention is to provide a method of installing solar cell modules, which enables the solar cell modules to be readily replaced on a piece by piece basis and a plurality of solar cell modules to be installed in a short time.
Still another object of the present invention is to provide a solar cell module capable of being easily connected to a ground wire at a low cost, and a grounding method thereof.
The first aspect of the present invention is a solar cell module which is to be connected to a cable constructed by sealing a core wire with a coating and comprises a connecting member to be passed through the coating of the cable and electrically connected to the core wire of the cable. The solar cell module of this first aspect comprises the connecting member to be passed through the coating of the cable and electrically connected to the core wire, makes an electrical connection easily, and requires no connector which is used in prior arts, thereby reducing the cost. Moreover, since the connecting member is buried in the coating of the cable, the connected section ensures a high waterproof property.
The solar cell module of the first aspect comprises a supporting body for supporting a solar cell portion, and the connecting member is supported on the supporting body. Since the connecting member is provided on the supporting body for supporting the solar cell portion, this solar cell module is easily carried, thereby improving the work efficiency.
The connecting member of the solar cell module of the first aspect is a pair of positive and negative connecting members to be electrically connected to a pair of positive and negative core wires of the cable. By electrically connecting the pair of positive and negative connecting members to the pair of positive and negative core wires of the cable, respectively, a plurality of solar cell modules are connected in parallel.
The second aspect of the present invention is a solar cell module which is to be connected to a cable constructed by sealing a core wire with a coating and comprises: a pair of positive and negative connecting members to be passed through the coating of the cable and electrically connected to the core wire of the cable; and a cutting member for cutting the core wire of the cable connected to the pair of positive and negative connecting members between the pair of positive and negative connecting members. According to the solar cell module of this second aspect, since the cutting member cuts the core wire of the cable between the pair of positive and negative connecting members electrically connected to the core wire of the cable, a plurality of solar cell modules are connected in series.
The third aspect of the present invention is a method of connecting the solar cell module of the first or second aspect to a cable, wherein the solar cell module is connected to the cable by pressing the connecting member of the solar cell module to pass through a coating of the cable and come into contact with a core wire of the cable. An electrical connection of the solar cell module with the cable is made by pressing the connecting member of the solar cell module to pass through the coating of the cable and come into contact with the core wire. Therefore, an electrical connection is easily made, and a low cost is realized because no connector which is used in prior arts is required. Furthermore, since the connecting member is buried in the coating of the cable, the connected section ensures a high waterproof property.
The fourth aspect of the present invention is a method of installing a plurality of solar cell modules to overlap each other on an installing body, wherein the solar cell modules are arranged so that a lower portion of the solar cell module on an upper side and an upper portion of the solar cell module on a lower side overlap each other, and each overlapped portion is fixed to the installing body by a screw fixation. The overlapped portion of the lower portion of the solar cell module on the upper side and the upper portion of the solar cell module on the lower side is fixed to the installing body with a screw. The lower-side solar cell module can be easily detached by loosening the screw, and it is therefore possible to readily replace the solar cell modules on a piece by piece basis. Besides, a large number of solar cell modules can be installed in a short time.
In the method of installing solar cell modules of the fourth aspect, an electrical connection of the lower-side solar cell module with a cable is made by the screw fixation. In the process of fixing the upper- and lower-side solar cell modules with a screw, the lower-side solar cell module is electrically connected to the cable. Therefore, the fixation process and the electrical connection process are achieved simultaneously, and the installation of the solar cell modules is performed efficiently. Moreover, the electrical connection is easily cut by simply loosening the screw.
The fifth aspect of the present invention is a solar cell module which is to be connected to a ground wire constructed by sealing a core wire with a coating and comprises a ground connecting member to be passed through the coating of the ground wire and electrically connected to the core wire of the ground wire. Since the solar cell module of this fifth aspect comprises the ground connecting member to be passed through the coating of the ground wire and electrically connected to the core wire, it is possible to make an electrical connection easily.
The solar cell module of the fifth aspect comprises a supporting body, made of a metal, for supporting a solar cell portion, and the ground connecting member is supported on the supporting body. Since the ground connecting member is provided on the supporting body for supporting the solar cell portion, this solar cell module is easily carried, thereby improving the work efficiency.
The sixth aspect of the present invention is a method of connecting the solar cell module of the fifth aspect to a ground wire, wherein the solar cell module is connected to the ground wire by pressing the ground connecting member of the solar cell module to pass through the coating of the ground wire and come into contact with the core wire of the ground wire. An electrical connection of the solar cell module (supporting body) with the ground wire is made by pressing the ground connecting member of the solar cell module to pass through the coating of the ground wire and come into contact with the core wire. It is therefore possible to readily grounding each solar cell module.
The seventh aspect of the present invention is a method of installing the solar cell module of the fifth aspect on an installing body, wherein connecting the ground connecting member to the supporting body is carried out by a screw fixation, and installation of the solar cell module on the installing body is achieved simultaneously with the screw fixation. The supporting body of the solar cell module and the ground connecting member are electrically connected by a screw fixation, and the solar cell module is installed/fixed on the installing body simultaneously with this screw fixation. Hence, there is no need to perform a special process for connecting the supporting body and the ground connecting member, and a ground connection is made efficiently.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.